128 research outputs found

    Coastal Landscapes of South Australia

    Get PDF
    This book aims to assist people in interpreting coastal landforms in South Australia, revealing how the coast has evolved and is continuing to do so under the influences of a range of processes acting upon a variety of geological settings. South Australian coastal landforms include cliffs, rocky outcrops and shore platforms, mangrove woodlands, mudflats, estuaries, extensive sandy beaches, coastal dunes and coastal barrier systems, as well as numerous near-shore reefs and islands. Geologically, the South Australian coast is very young, having evolved over only 1% of geological time, during the past 43 million years since the separation of Australia and Antarctica. It is also very dynamic, with the current shoreline position having been established from only 7000 years ago. This book is a landmark study into the variable character of the South Australian coast and its long-term evolution

    Depositional history and archaeology of the central Lake Mungo lunette, Willandra Lakes, southeast Australia

    Get PDF
    Lake Mungo, presently a dry lake in the semi-arid zone of southeastern Australia, preserves a unique record of human settlement and past environmental change within the transverse lunette that built up on its downwind margin. The lunette is \u3e30 km long and the variable morphology along its length suggests spatial variability in deposition over time. Consequently this presents differential potential for the preservation of past activity traces of different ages along the lunette. Earlier work at Lake Mungo focused primarily on the southern section of the lunette, where two ritual burials of considerable antiquity were found. Here we describe the depositional history of the central section of the Lake Mungo lunette, together with the first single grain optically stimulated luminescence (OSL) chronology of the full stratigraphic sequence and of three hearths. We thereby lay the foundation for systematic investigation of the distribution of archaeological traces through the sedimentary record. The older depositional units (Lower and Upper Mungo) were deposited ca. 50–40 ka and ∼34 ka respectively, and are substantially thinner in the central section of the lunette compared with the south. By contrast, the overlying unit of interbedded sands and clayey sands (Arumpo–Zanci units), deposited ca. 25–14 ka, is markedly thicker and dominates the stratigraphic sequence in the central portion of the lunette. Although the sequence broadly reflects previous models of the lunette\u27s depositional history and changing hydrological conditions, our results indicate spatially variable deposition of sediments, possibly as a result of changes in prevailing wind regimes. Archaeological traces are exposed in all stratigraphic units deposited after ca. 50 ka, including sediments deposited after the final lake drying ca. 15 ka, indicating human occupation of the area under a range of palaeoenvironmental conditions. Dating and stratigraphical examination of individual hearth features demonstrates that even within individual stratigraphic units, human occupation persisted under variable conditions. Mid-Holocene occupation of the area following the final lake retreat took place during a period of relatively humid climate

    Coastal Landscapes of South Australia

    Get PDF
    This book aims to assist people in interpreting coastal landforms in South Australia, revealing how the coast has evolved and is continuing to do so under the influences of a range of processes acting upon a variety of geological settings. South Australian coastal landforms include cliffs, rocky outcrops and shore platforms, mangrove woodlands, mudflats, estuaries, extensive sandy beaches, coastal dunes and coastal barrier systems, as well as numerous near-shore reefs and islands. Geologically, the South Australian coast is very young, having evolved over only 1% of geological time, during the past 43 million years since the separation of Australia and Antarctica. It is also very dynamic, with the current shoreline position having been established from only 7000 years ago. This book is a landmark study into the variable character of the South Australian coast and its long-term evolution

    The chronostratigraphy of a Holocene Barrier Estuary: Lake Illawarra NSW

    Get PDF
    Valley-fill sequences, preserved in topographic lows associated with incised valley systems, potentially preserve a record of Holocene sea level fluctuations. A detailed litho- and biostratigraphy of the Holocene barrier estuary, Lake Illawarra, New South Wales has been constructed. Forty kilometres of seismic surveys, forty-one vibracores, supplemented by auger drill holes and trenches, and faunal analysis provides the data for this investigation. A detailed chronology of the infilling of the barrier estuary has been established using 115 aspartic acid derived ages and six radiocarbon ages. The results provide a detailed chronology for the deposition of marine transgressive deposits, barrier growth, and the subsequent development of the estuarine back-barrier environment. The results from Lake Illawarra indicate that the generalised evolution of the barrier estuary occurred in five geomorphologically distinct phases associated with rising sea levels following the last glacial maximum (LGM)

    Last interglacial (MIS 5e) sea-level determined from a tectonically stable, far-field location, Eyre Peninsula, southern Australia

    Get PDF
    The last interglacial maximum (Marine Isotope Substage 5e [MIS 5e], 128¿116 ka) is a distinctive event in recent Earth history. Shoreline successions of this age are important for calibrating climate models and defining the overall behaviour of the crust¿mantle system to fluctuating ice and ocean-water volumes. In a global context, the recently intensified interest in last interglacial shoreline successions has revealed considerable variability in the magnitude of sea-level rise during this time interval and highlighted the need to examine paleosea-level evidence from tectonically stable, far-field settings. Situated in the far-field of continental ice sheets and on the tectonically stable Gawler Craton, the 300 km coastal sector of western Eyre Peninsula between Fowlers Bay and Lake Newland in southern Australia represents an important region for defining the glacio-eustatic (ice-equivalent) sea-level attained during the last interglacial maximum based on the relative sea-level observations from this region. Low-energy, shoaling upward, peritidal bioclastic carbonate successions of the last interglacial (locally termed Glanville Formation) formed within back-barrier, estuarine¿lagoonal environments in the lee of eolianite barrier complexes (locally termed Bridgewater Formation) along this coastline. The well-preserved shelly successions (coquinas) contain diverse molluscan fossil assemblages including species no longer living in the coastal waters of South Australia (e.g. the Sydney cockle Anadara trapezia and the benthic foraminifer Marginopora vertebralis). The extent of amino acid racemisation (a measure of fossil age based on increasing d/l value) in a range of species, and in particular A. trapezia and Katelysia sp., confirms the time equivalence of the isolated embayment-fill successions, correlated with the informal type section of the Glanville Formation at Dry Creek, north of Adelaide. Preliminary U-series analyses on A. trapezia also suggest a correlation with the last interglacial maximum, but further highlight the complexity in dating fossil molluscs by the U-series method in view of their open-system behaviour. The shelly successions of the Glanville Formation occur at elevations higher than attained by sea-level in the current, Holocene interglacial. A higher sea-level of between 2.1 ± 0.5 and 4 ± 0.5 m above present sea-level is inferred for the last interglacial maximum (MIS 5e) along this coastline based on the elevation of sedimentary successions host to the shallow subtidal¿intertidal fossil molluscs Katelysia sp., and Anadara trapezia. The paleosea-level observations place a lower limit on the sea-level attained during the last interglacial maximum and suggest that caution be exercised in the definition of the upper limit of sea-level during this interglacial

    David Quentin Bowen: A memorial

    Get PDF
    The Quaternary community lost a giant and a leader on October 5, 2020, when David Quentin Bowen, known to many as “DQ” and founding editor of Quaternary Science Reviews, passed away in Cardiff. Born on February 14, 1938 in Llanelli, SouthWales, he received his PhD at University College London. David’s 50 years of contributions to our science cannot be adequately summarized in a brief memorial but past, present, and future generations of Quaternary scientists will long remember his landmark achievements in publishing, his scientific contributions, and his personal and professional class in all his endeavors

    Deception and Self-Deception

    Get PDF
    Why are people so often overconfident? We conduct an experiment to test the hypothesis that people become overconfident to more effectively persuade or deceive others. After performing a cognitively challenging task, half of our subjects are informed that they can earn money by convincing others of their superior performance. The privately elicited beliefs of informed subjects are significantly more confident than the beliefs of subjects in the control condition. By generating exogenous variation in confidence with a noisy performance signal, we are also able to show that higher confidence indeed makes subjects more persuasive in the subsequent face-to-face interactions

    New genetic loci link adipose and insulin biology to body fat distribution.

    Get PDF
    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
    corecore